The Silver Tree
by Mayanwolfe
Summary: When Amy and Rory delve deeper into the TARDIS than ever before, they unleash an unstoppable relic from the Doctor's greatest battle, and even the Time Lord himself may not be able to stop it.
1. Lost Time

(This is my first attempt at writing fanfiction, so I would very much appreciate constructive criticism on my technique and adherence to canon. Also, I'm an American trying to write for a UK show, so please help me correct any cultural mistakes as well!)

In a rare moment of peace, Rory Pond found himself feeling rather happy. He was sitting in the TARDIS kitchen, which currently appeared as though it were in a rustic old farmhouse, complete with a thick oaken table. The room was quiet, except for the constant thrum of the engines, and Rory sat alone with his thoughts, munching on a packet of some alien snack he had found in the pantry. The TARDIS helpfully translated the label as something like "kelp flakes," but he found them quite delicious.

With a clatter and thump, Rory's wife made her entrance. Amy was dressed in full rock climbing gear, complete with helmet, nylon harness, and a few more karabiners than might have been absolutely necessary. The whole ensemble made a tremendous racket, and Rory held his ear with one hand while he picked up his bag of kelp flakes from the floor.

"Ugh, Rory, darling, you startle way too easily. Believe me, once you've spent much more time with the Doctor, you'll start to get over that reflex. And what on Earth are you eating?"

Rory paused with a flake halfway to his mouth. "A nutritious snack?" he ventured.

Amy spun the bag around. "Oh, I remember these. The Doctor got the munchies on Algas 4 and bought them from a squid man on a street corner. He said they're all the rage with the local crustaceans. Though the fact that the main ingredient is processed lake scum does seem to put some people off a bit."

"The TARDIS said it was kelp! Like clean, nutritious, sea plants! Okay, I guess I don't even know why I wanted to eat them in the first place. 'Scuse me, I have to go brush my teeth."

Amy put her hands on his shoulders and gave him a quick kiss. "No, you don't. There, all better. Now come on, I feel like taking a walk."

"Um, I don't generally include 'Dangling from 50-foot cliffs' on my list of things to do on a walk."

Amy glanced down. "Oh yeah, the mountaineering stuff. I found a whole new room that's just covered in climbing walls. The TARDIS even made me the harness. Look, have you ever thought about how big this place must be? The Doctor said it's like a 'pocket dimension,' so there can be as many rooms as he wants! Imagine what's hidden away in the corridors that everyone's forgotten."

She began to strip off her harness and gear and put it on the large oaken table. Rory watched her thoughtfully. "Amy," he said finally, "what time is it?"

She paused. "What do you mean? It's late afternoon in Leadworth time, I think. Why?"

Rory began to walk around the room, peering beneath the rustic cabinetry. "Have you ever felt like we're losing track of our lives in here? Before you came in I was just sitting there, eating those fish flakes, and thinking about how I didn't have to worry about all the mundane things that normal people think of every day. You know, like bills and taxes, and the daily post and the neighbor's dog. None of it matters! And then I realized I didn't even know what time of the day it was. We just sleep and eat and go on adventures whenever we feel like, and adjust ourselves to whatever planet we happen to land on. What if we get back to Earth and it's more alien than this place? Ah, here we go."

He tilted his head at an extreme angle to read the small chronometer wedged beneath a spice rack. A wry laugh escaped his throat. "It's four in the morning. And we had no idea."

Amy, now free of all her clattering gear, turned him round to face her. "Rory, that's the beauty of this place! It can put incredible wonders at our fingertips but it can also take us home anytime. We can be as grounded as we want to be. Tell you what - we'll go for a walk, we'll find the Doctor, and we'll tell him we want to go home, just for a bit. We'll go round my parents', have a chat and some of Mum's rubbish tea, go back to our place and _enjoy ourselves_ for a day or so, then call up the Doctor and he'll come pick us up."

Rory looked unconvinced. "But what if he never comes back? You'd never forgive me and I'd never forgive myself. Un-forgiveness overload."

Amy kissed him once more, a quick peck on the nose. "You stupid man, of course he'll come back. He always comes back. Now let's go."

She grabbed him by the hand and, together, they left. The TARDIS automatically dimmed the lights and began absorbing the discarded climbing gear and packet of kelp flakes into its raw material matrix for later use. Then, for a lark, it rearranged the kitchen's appearance into that of a quaint French bistro. After all, there's never a bad time for a crepe.

Next Time: Amy confesses a crime, the TARDIS is holding secrets, and an adventure begins.


	2. Forgotten Places

(Thanks to everyone who read so far!)

Amy and Rory walked down yet another well-lit TARDIS hallway, indistinguishable from all the others except for the occasional section and level number stenciled on metal plates inset into the wall. They still weren't sure how many levels there actually were, and the Doctor got rather cagy when they asked. It seemed that he had no idea either. Fortunately, the TARDIS was always happy to display a holo-map that would show them the way back to the control room. This time, however, Rory noticed that his bride was studying a small data pad instead. It looked very much like the one he had seen River Song use. For all he knew, the timelines around the Doctor and River were so skewed, it might be the same one.

"Um, where did you get that?" He noticed that the map Amy was studying most definitely did not lead back to the control room. In fact, it was a longer distance than either of them had traveled inside the vast machine. "Aren't we going to talk to the Doctor?"

Amy looked up at him and smiled, but a deep blush was spreading from her cheeks all the way up to her hairline. "Well…I thought we would do that after we took our walk. Besides, I'll have to return this to him anyway." She waggled the data pad.

"You mean you _stole_ it?"

"Well, not really. Remember a few days ago, after we stopped that Judoon invasion on Hyra, how we were so exhausted and went right to bed? Well, I couldn't sleep so I went to the control room to mess with the scanner for a bit. The Doctor was there, completely passed out in one of the chairs by the console! He'd been fixing some gadget with his sonic and fallen asleep. Up till then I wasn't even sure Time Lords slept at all. Well, I was turning to go when I saw this pad had fallen out of his pocket. It was still on, and I picked it up and started looking through it. It's nosy, and rude, and I should return it right away, I know, but you'd never believe what's on it! I think it's a complete map of the TARDIS!"

She showed the pad to Rory, and sure enough, the endless maze of tunnels was projected there. Amy gestured, and the levels zoomed past with no end in sight.

'Okay, that is pretty brilliant, but you need to give it back. Why haven't you, anyway?"

Amy drew closer, as if the roundels on the walls were hundreds of listening ears. "Because the maps on this pad don't match the ones the TARDIS shows us. According to this, there are loads more passageways that the Doctor doesn't want us to know about. Like this one."

With a few more gestures, she called up the route she had been studying before. It ended at what appeared to be a simple cul-de-sac on Level -239. However, this particular passage, instead of being charted in cool royal blue like all the rest, was outlined in stark black.

"Don't you want to know what's hidden there?"

"Not particularly. Doesn't black generally mean, I dunno, death? What if it's filled with toxic mustard gas or something and we choke our lungs out as soon as we open the door?"

Amy gave him a look he recognized all too well. It was the "you're being at idiot, now shut up" look. "Come on, Rory, it's the TARDIS. It's the Doctor's home. He wouldn't have anything here that could hurt us."

"Yeah, it's not like we don't get enough of that already on every single planet we land on." He let Amy grab his hand again, however, and lead him toward the lift that would take them down into the depths of the TARDIS and the darkness that waited there.

Next Time: The Seal of Rassi-wotsit, the enemy's shadow, and the forgotten heart.


	3. Shadow of the Enemy

(Thanks to everyone who's read so far! Okay kids, this is where it gets complicated!)

As the lift sped downward, Rory felt his heart, not to mention his lunch, rise into his throat. Judging by the death grip Amy still had on his hand, she felt the same. Neither felt able to speak, so they just watched the red numbers above the door count down the levels until they were moving so fast that they merged into a sickening red blur. Rory felt his weight shift upwards until they were nearly in free fall. For a moment, he wondered if the TARDIS suspected them of poking their noses where did didn't belong (and in his case that was quite an intrusion), and was trying to kill them off. No sooner did this cross his mind, however, than the lift began to slow, and the display finally settled on Level -239.

Amy smiled at him. "Now that wasn't so bad, was it?" Her face was completely white.

The lift doors opened on to a short hallway…and another door. This one spanned the entire distance from floor to ceiling and its great face was etched with a massive, black symbol.

"Hey, I recognize that," Amy said. "It's the Seal of Rassi-wotsit…Don't look at me like that! I really can't remember the name. I saw it on some stuff the Doctor was stowing away under the deck plates in the Blue Room. It's some Time Lord insignia or something. Why won't this door open?"

All of the TARDIS doors were automatic, and to Rory's dismay, sounded nothing like the ones on Star Trek. This door, however, was apparently not programmed to let them pass. Amy fiddled with the data pad until it clicked and extruded a pronged interface which she plugged directly into the door control. Rory looked at her askance.

"You used to ring me if you had to change a light bulb. Now you're picking locks on an alien spaceship with technology that hasn't been invented yet. What has the Doctor done to you?"

Before she could reply, the door control clicked and massive seal split in two to reveal the passage beyond. It was dark, and the chilled air that spilled out made gooshflesh prickle on their arms. At this point, Rory felt his resolve dwindling, but an intense curiosity was beginning to grow in the back of his mind. What did the Doctor have to hide? So, to his surprise, when Amy stepped inside the hallway, he found himself following close behind.

True to every horror movie imaginable, as soon as they crossed the threshold, the massive door slammed closed. Amy held the data pad up like a torch, casting a blue glow that reflected off the dull metal walls. Their breathing seemed magnified by the dark.

Okay, Rory thought, this is the point when any sane person would turn around and get the hell out of here. So why aren't we? Because the Doctor's made us just as crazy as he is, that's why.

Amy tilted the pad in his direction. The display glowed so brightly in the darkness that it left multicolored streaks on his retinas. "Look, it's just a short little passage. We go around this bend and check out whatever's in this little room, then we come right back. Piece of cake." She began to step carefully forward, using the pad to light her way.

Rory hung back for a moment, and ran his hand across one of the clouded glass roundels on the wall. His fingers came away coated in a fine black powder, like the soot left over from a fire, or a lightning strike. The air, too, smelled strange. On top of the staleness there something sharp, metallic. Rory remembered one night when he and Amy were ten; they had been playing behind Mr. Halloran's barn when a sudden electrical storm took them by surprise. They'd huddled in the barn for an hour while the lightning crackled all around, and the air smelled exactly the same. Charged, somehow.

Suddenly, Amy screamed, and the sound reverberated madly off the passage walls.

Rory ran blindly forward and nearly bowled her over. She grabbed onto his shirt in a frenzy and when he saw what she did he wished he had someone to cling to as well. Just around the bend in the corridor, something was projecting a shadow. The shadow was short and hulking, with a single narrow eyestalk on top and two arms in the middle capable of dealing death in a single shot. Rory froze, waiting for the single word and flash of light that would end his life and Amy's, but there was only silence, aside from their ragged breathing. "Is it dead?" Amy asked, loosening her grip on his shirt.

Rory inched forward. The shadow still didn't move. As he rounded the curve, the beast itself became visible. It was a Dalek, but it was also very clearly dead. It sat to one side of the hallway, a copper corpse, still terrifying despite the jagged rip that had cleaved its metal body nearly in two. Amy edged forward and touched the blackened, serrated edge of the cut. "Why is there a Dalek in the TARDIS?" she whispered.

"And what sort of weapon could just cut one in half like that? When I was Plastic my gun barely slowed them down," Rory said, "Also, what were you saying to me earlier about that 'startle reflex'? 'Cause it seems to me that…"

It was then that he looked up and saw where the passageway had led them. Amy looked up too, and her face filled with wonder. "No way," she said, as she took in the vaulted room before them, "It's…a second heart…"

Next Time: Mementos of times past, the Silver Tree, the Possession of Amy Pond, and a Rescue.


	4. The Broken Heart

(Sorry about the delay in publishing this chapter. Final exams jumped on me like the Doctor on a brand new hat! Hopefully the fact that it's a bit longer makes up for the wait.)

"Well, that was melodramatic," Rory said to Amy, after swallowing several times, "but also pretty bang on. Why the _hell_ does the TARDIS have a second control room all the way down here?"

The room was small in circumference, but the ceiling extended so far overhead that it was hidden in the gloom. The center was dominated by a very familiar-looking hexagonal console illuminated by a ring of blue spotlights. Very sturdy-looking girders arched up from the floor and anchored the central column.

"Maybe if the main one gets destroyed, or something, the Doctor's got a ready backup."

"No, hold on, I don't think anyone's bothered with this room in a long time."

Rory ventured forward toward the console. Beneath the eerie blue glow of the spotlights, he could see that all of the switches and dials were covered with the same black soot he'd noticed earlier on the wall. Amy came up beside him, and before he could react, she picked a switch at random and flipped it. He flinched, but absolutely nothing happened.

"Y'know, we could have been flung off into deep space or something," he said.

"We're already in deep space. Besides, how many times do I have to tell you that the TARDIS is safe? It's alien, but above all I think it wants to protect us."

"You'll have to keep reminding me of that every time some _other_ piece of alien tech tries to hold us hostage and/or end the universe."

Amy had already stopped listening, however, and was marveling at what lay around the edges of the room. Aside from the futuristic console, at first glance the rest of the ersatz control room would be right at home in a gothic novel. Claw-footed tables and comfortable chairs rested on the polished wood floor. Ornate candelabras stood at intervals, aided by blown-glass bulbs extending from the walls on arched supports. It was more like being in a famous historical figure's home than an interdimensional spaceship.

This posh setting, however, was marred by obvious signs of decay. The floor was scarred, scuffed, and dull with dust. The chairs were ripped and broken, and the tables were piled high with grimy junk. Amy walked over to the nearest table and picked up a small hardwood box which had been balanced on top of a stack of yellowed paper. The dark red wood of the box still shone despite its age, and the seal engraved upon the lid was instantly recognizable.

"It's got the same symbol as the door outside. In fact, a lot of this stuff does. It's everywhere! Rory, all of these things are Time Lord artifacts! How cool is this!" Amy began to search about the room, finding more and more instances of the seal. Her hand slid the box into her jacket pocket.

Rory went back to the console. Something about it was unnerving him. He scraped some more of the soot off the surface. After a moment, he saw it: crisscrossing the console at random intervals were thin, jagged scorch marks, as if a madman had been let loose with a blowtorch. Some of the beautiful woodwork, he now noticed, carried the same marks. What had happened here? A small hardwood box, identical to the first one, was resting against some of the switches. Rory's eyes passed over it without stopping.

"Whenever the Doctor breaks something on the TARDIS," he said, half musing, "It just absorbs it and spits it back out good as new, but here…" His hand picked up the second box.

Amy heard him and caught his drift. "Here, everything stays broken and begins to crumble. It's like the room the Doctor forgot. On purpose, too, it looks like. He just piled all of this Time Lord stuff in here and…locked the door behind him."

They both stood quietly for a moment. Rory now felt like worse than a trespasser behind locked doors; he was a trespasser behind locked memories. Whatever curiosity he'd gained throughout their little adventure vanished in an instant. "Let's go," he said. "We need to leave, right now."

Amy nodded and joined him. Together, they started for the door…then stopped. Rory felt the new weight in his pocket, and reached in to find it, watching Amy do the same. They held up the identical hardwood boxes that neither could remember taking. The silver Seal of Rassilon shone like tropical ocean water beneath the blue spotlights.

"Well, this isn't weird at all," Amy quipped, but her voice shook.

"Nope, not highly disturbing in the least." Rory felt like his feet had been glued to the floor. The box was held closed by a simple clasp; just one flick and it would open. He looked at his wife and saw that she hadn't made any attempt to solve this latest mystery. Despite her worrisome trust in the Doctor's alien gadgets, she was still a sharp cookie. Never trust a creepy box. Suddenly, the wood beneath Rory's fingers began to grow warm, escalating to scalding within the space of a second. He yelped and dropped the box, which fell to the floor with a clatter. Amy barely had time to register confusion before she yelled and dropped hers as well, shaking blistered fingers. Both boxes lay on the hardwood floor, split open from the impact, their silvery contents laid bare at last.

Rory had to admit, it was a bit of a letdown. Compared to some of the things they'd seen - from talking pepperpots to maniacal computers the size of Crispex - this was nothing. He managed a laugh. "It's just bits of metal! Like, a sculpture or something."

Amy bent down and picked up both objects. They looked to be made out of hundreds of tiny metal filaments, like silver spaghetti, shaped and threaded and wound upon themselves until they each formed something like half of a mushroom cloud, split cleanly down the middle. They were about the size of a human palm. and actually quite pretty. He ventured his description.

Amy snorted. "You boys, always so violent. Can't you see? It's not a mushroom cloud at all, it's a tree. A little silver tree." She smiled. "Maybe it's like the Time Lord version of those cheesy heart necklaces that couples give each other, y'know, one person takes one half and the other person takes the other, and when they meet they're supposed to fit together perfectly. A bit too mushy, if you ask me." She clasped the two split halves of the object together for emphasis.

Rory swallowed. "Um, remind me to exchange your birthday gift."

Amy laughed, and Rory felt smile spread reluctantly across his own features. Some of the tenseness that had been building in his chest seemed to loosen. Until he saw movement in his wife's palms. The metal fibers that made up the object were slithering across each other and seemed to be knitting together. After only a moment, however, they stopped. Amy, looking more intrigued than scared, held the little tree up closer to her face. "Hey, I can see something in the center, between the fibers. It's like a little blue light that keeps blinking on and off. I wonder what it means? Oh wait, it's stopped. Now it's gone...mauve?"

Rory opened his mouth to tell her to drop it, to let it go, to do something, but he was too late. The mauve light exploded outward and so did the fibers. They wrapped themselves around Amy's hands like a malevolent vine, twining her fingers together with silvery strands. The tree continued to flow outward and downward, spreading with unnatural speed and following the path up her arms toward her body. Rory lunged forward and tried to pry away the filaments, but it was like bending solid steel. The silver stream continued to flow upward, and Amy whimpered in its grasp. The strands were beginning to feel around the edges of her long red hair, nosing their way along in a manner that was intelligent, yet horribly alien. Rory heard himself talking, muttering useless platitudes and curses, while he scrabbled uselessly at her hands, arms, fingers. Amy tilted her head back as far as she could, but the roots of the tree spread and tickled with cold fingers until they found their way into the soft recesses of her mouth and nose. She screamed, and Rory saw the silver flow across her tongue.

An indescribable noise escaped Rory's throat, and without thinking, he spun around and ran back to the dead TARDIS console. Trying to ignore the soft sounds of flowing metal behind him, he began flicking switches and pushing buttons at random, hoping that something, anything would spring to life and somehow send help. There was something like a viewscreen. He smacked it with the heel of his palm, and to his utter surprise, it lit up in a haze of static. "Doctor! Hello? Can anyone hear me? Please help, I dunno what's happened but something's got Amy. Look, I don't care who you are, just send help! Doctor! Are you there?" The screen hissed and crackled, bu no face appeared, and no voice rang out. Rory continued to shout, while not far away, the silver tree sunk its roots deep into the heart of Amy Pond.

(Well, I guess I didn't quite get into the last segment of my Next Time ticker, but that'll just have to wait until the next chapter, which I hope to post very soon!)

Next Time: A Rescue, The Greater of Two Evils, and History Never Dies.


	5. Help from Above

(Hm, it seems that the phenomenal episode "The Doctor's Wife" has rendered some of my plot points moot. Oh well, I'm still having fun, and Neil Gaiman can steal my ideas any day!)

Rory felt like all his insides were forcibly rearranging themselves. The viewscreen continued to hiss and crackle with gray, meaningless static, and Amy had slid silently to the floor. Rory gave one last shout and smack to the screen before rushing back to his wife.

Amy's head, when he moved to place it in his lap, was far too heavy, and he could see movement, like waves, just under her skin. The tree was growing inside her, spreading out tiny silver feelers and turning her into who knows what. Rory had absolutely no idea what to do. It was as if his brain had been suddenly wiped blank, like taking a magnet to a hard drive. There was no way he could drag her to the lift; she was growing heavier every second as the tree claimed its new territory. He pushed a lock of hair off her face. Some of the strands shone silver.

There was a sharp squawk from the direction of the console and Rory jumped. A horrible electronic screech rang out, followed by the familiar hum of a sonic screwdriver. The static on the viewscreen was arranging itself into recognizable shapes. Rory laid Amy's head gently back on the floor and tried to get up. Her newly gained weight had cut off the circulation to his left leg entirely and he staggered sideways, cursing. Meanwhile, the screen cleared of static for just a moment and displayed three words. They glowed brightly, then disappeared, but they were all Rory needed to see:

| DUCK, PONDS! GERONIMO! |

A faint clattering sound come from somewhere up above, getting louder all the time, accompanied by a long, sustained yell of what could only be delight. In the shadowed ceiling a hatch opened, and a gangly shape came plummeting down to land on a pile of yellowed papers. A large cloud of debris quickly followed. The Doctor stood up, brushing copious amount of dust off of his lapels and grinning so widely that Rory felt the urge to punch him. After all, it had felt pretty good the first time.

"Well, that was exciting," the Doctor said. He felt the small of his back and winced. "Okay, painful, but exciting. I got your distress call and had the TARDIS reroute all the ventilation shafts to your location. I jumped down one of those holes in floor of the control room and off I went!" He made a swooping motion with one hand. "Exactly like a water slide, except with no water and lots of dust. Okay, nothing like a water slide. Now, where the hell am I, and what's happened to Amelia?"

The Doctor bent down next to Amy, scanning her briefly with the screwdriver. After a long moment, his shoulders slumped, and Rory's blood turned to ice. The Doctor looked up and took in his surroundings for the first time, letting his eyes rest on every major feature before they fell on Rory. He seemed to be about to say something, but changed his mind and pulled a white handkerchief from one of his depthless pockets. "Here, clean yourself up. You look terrible. Let me worry about Amy for a moment."

Rory took the proffered kerchief and wiped his face. It came away covered in soot and quite wet. He touched his cheek. He hadn't been aware that he was crying. "Doctor, what's happened to her? Can you fix it?"

The Doctor ran a hand through his hair. He suddenly seemed very old. "The Time War happened to her, in a way. History never dies, of course I, of all people, should know that. Can I fix it? 'Course I can. But…well, we'll cross that bridge when we come to it." He clapped his hands and rose, a kind of resolution in his steps as he walked over to the dead control console. Rory heard him whisper something - it sounded like an apology - then he plunged his sonic screwdriver deep into a damaged panel. After a few moments he pulled it out, and the green tip now glowed with some sort of crackling blue energy. The Doctor walked back to Amy, holding the screwdriver as if it were a live grenade. "Artron energy," he said, "the lifeblood of the TARDIS." He knelt again beside Amy. "This should be all it takes."

He held the tip of the screwdriver close to Amy's still face, giving her skin an eerie cast. She twitched, and Rory gasped. The silver strands were reappearing from Amy's mouth, ears, and nose. They sought out the sonic, but the Doctor moved it farther back. More and more of the silver stuff began to flow; a hundred thousand hairlike fibers twisting and turning and following the Doctor as he walked backward, slowly, toward the center console. When he was about three steps away, he stopped, took a deep breath, and threw the screwdriver the remaining distance. The strands dove after it in a way that reminded Rory of a Labrador retriever chasing a stick. Both objects hit the console together, in a shower of sparks.

The silver stuff pooled and swarmed, and to Rory's amazement, it began to sink into the surface of the console itself. More sparks exploded outward, and both men ducked. After a few moments, the room grew still again. The console looked exactly the same, if slightly more scorched, but the Doctor's face told Rory that things were most definitely not back to normal. No time to worry about that, though. He rushed to Amy's side, and felt like he might melt right into the floorboards when she coughed and slowly opened her eyes. "Amy! Are you all right?"

She made a face. "Yeah, I think. I feel like I just lost a boxing match with a Cyberman and then tongue-kissed him afterward."

"That's disgusting. I love you so much." They hugged each other and laughed. The Doctor stood watching them, unsmiling, one hand fiddling absently with his bow tie.

"Doctor," Amy said, "that silver thing, I could feel it moving inside me, but I couldn't move. What was it? And what did you do to it?"

The Doctor turned back to the dead console and leaned against it. His voice was low. "That was a TARDIS killer. And I just let it loose on my ship."

Next Time: Infection, Justification, and Confusion.

(Just a friendly reminder that I'm always trying to improve my skills, so I really appreciate constructive criticism. Thanks to everyone who's read so far!)


	6. Guilt Trips

(Thanks for your patience, dear reader! I just got back from a lovely vacation in the mountains with poor internet access. Also, this chapter took me three rewrites to get the proper tone. ^_^)

Rory froze. "A TARDIS killer…what do you mean?"

The Doctor swept his hair back from his face. "Exactly what it says on the tin, Rory. A TARDIS killer. A killer of TARDISes. Thought you might have got that the first time."

Rory winced inwardly as he felt the cut from the Doctor's tone. He helped Amy to her feet. "We're sorry, Doctor. We had no idea that there was anything actually dangerous down here. It was just a little exploration."

"Well, that's lovely to know. You're sorry. I'll keep that as consolation while my beautiful interdimensional ship is slowly consumed from the inside out. At least _you were sorry._" The dead console began to creak and groan. The Doctor laid his hands on it as if it were the arm of a sick relative.

"But if this Tree thing thing is so dangerous, why keep it around at all?" The defiant streak in Amy's voice sent another surge of affection through Rory.

The Doctor looked at her like he'd never seen her before, and a small smile pulled at his lip. "Quite right, why indeed." He picked up his sonic from the smoking console and tapped her on the nose with it. "That's why I like you, Pond, you always ask the right questions. But that doesn't mean I have to answer them." He turned back to the console just as it emitted a series of sharp cracks.

Rory gasped and wrapped his arm more tightly around Amy's shoulder. Silver filaments were curling out of the ruined panels like time-lapse video of vines consuming a house. They threaded their way through the levers and dials, twisting and questing for something with inhuman intelligence.

"There's nothing for it here," the Doctor said. "This console is completely lifeless, just a husk. It wants a living, thinking, beating TARDIS heart to wrap its tendrils around. Once it's found its prey, it will stop at nothing to choke it to death." He clapped his hands together and rubbed them. "And as far as I'm aware, there's no way to stop it. Brilliant. I have absolutely no idea what to do, but that's never stopped me before. Come along, Ponds!" He spun on his heel and sprinted for the door.

Amy and Rory followed, but not before glancing one last time at the seething horror that was now consuming the console with ravenous precision. Silver feelers began to spread out onto the hardwood floor, heading toward their feet. They ran. The Dalek husk still lurked just outside in the hall, but now it seemed literally an empty threat compared to what lay behind them. Still, Rory couldn't resist one last look. The Tree's roots had reached the Dalek, and tendrils were beginning to climb its blackened skirt.

The lift felt crowded. Each person's individual guilt seemed to be taking up most of the space. The Doctor leaned against the wall, head tilted back and looking at the ceiling. No one said anything as the red numbers above the door counted down and the lift bore them upward. Just when Rory felt like he might implode from the tension, Amy spoke. Her voice was small. "It was my fault, Doctor. I dragged Rory down there after I found this." She held out the data pad containing the TARDIS map.

The Doctor's expression of shock quickly dissolved into anger. He snatched the pad from her and slid it inside one of his bottomless pockets. "You humans! You can't be content with all of time and space. You have to stick your grubby little fingers inside my memories, too." Rory didn't know what he meant, but didn't dare ask for clarification. The Doctor was a dynamo, now, crackling with furious energy. "You're like monkeys, poking a hive with a stick to see how long it takes before the bees fly out and sting you in the face!"

Amy looked as though she might cry. Rory felt a surge of protectiveness for his wife, granting him the courage to speak. "Okay, you might have a point, but remember that time with the Dream Lord and the homicidal old people? You literally said 'Something doesn't make sense, let's go and poke it with a stick.'" He made a poking motion. "Your words."

The Doctor opened and closed his mouth like a fish. Before he could think of a retort, however, the lights went out and the lift was plunged into darkness. A few seconds later, they screeched to a halt. The numbers above the door glowed faintly, frozen at Level -23.5. The Doctor's voice filtered somewhere out of the dark. "Well, this is just perfect. The roots of the 'tree' must have found their way into the lift power conduits and gobbled them up. I'd open the doors, but as you can see we're between levels right now. I'll send a telepathic message to the TARDIS, but it's going to take a few moments for her to reroute the power, as I suspect she's got rather a lot on her mind right now."

"Well, maybe now you can give us some answers," Rory said. He was feeling rather smug, despite the dark and the possible imminent doom. "What the hell is going on?"

They heard the Doctor blow a breath out of his nose. "Rory shows some backbone. I suppose I should be pleased. In a nutshell, that 'Tree' you set loose isn't a tree at all. It's more like a brain, except it made of metal and it devours whatever it touches. Okay, not like a brain at all, but you get my point. Just before it dove on Amy, you saw a blinking light, yeah? I'll just assume you're nodding right now. Well, that was the countdown. When it ends, the weapon is programmed to infest the nearest object, which is supposed to be a TARDIS. In this case, it was Amelia Pond. The only way I could save her was by transferring the Tree to a more suitable host. In this case, my TARDIS. Make sense? Again, I'm assuming nodding." There was a crunch of grinding gears, and the lift moved upward several feet. "Ah, wonderful. That's my girl. There should be enough space for us to scramble out and continue onward."

"But where are we going?" Amy asked.

The Doctor swiped his sonic at the door. In the brief flash of green they could see his grin. "To the control room, of course, 23 levels up. The old-fashioned way! By old-fashioned, I mean 'doing lots of running down corridors.' Ah-hah!" The doors hissed open. The Doctor scrambled though the narrow space the TARDIS had provided them and was gone.

Next Time: "Men never like to redecorate, do they?", "That's the fifteenth, I counted.", "The most depressing scrapbook in the universe."


	7. Ashes to Ashes

(This is a long chapter, I know, but I hope it's worth the read! Thanks to everyone who's read and enjoyed so far!)

Rory clambered up and out of the lift, scraping his knees as he did so. He reached behind to pull Amy up, but she was already right behind him. "Feeling better, then?"

"Yeah, loads. Still horribly guilty and all that, but I feel less like one massive bruise now. Come on, before the Doctor gets himself into trouble."

"Oh, I though that was pretty much his standard state of existence anyway." Amy was already on her feet and tugging on his shoulder. Rory let her pull him up, favoring his tender knees.

This particular corridor was a gentle curve with circular doors placed at regular intervals along its length. Rory couldn't make out the other end, and for all he knew, it went on forever. The Doctor, however, was only a short distance away, spinning in slow circles and consulting the data pad. Amy jogged up to him and peered over his shoulder, but tentatively, Rory noticed. She didn't rest her hand on his arm or her chin on his shoulder, as she usually would. She was clearly testing the waters of his mood. Rory hung back. Even though he'd known Amy for most of his life, many times he still felt like an outsider. He was cautious and practical, and those traits didn't seem to fit the world of the Doctor. "Hm, yet another gold and silver corridor," Amy said. "You wouldn't need that map if you'd change the color scheme once and again. But, men never like to redecorate, do they? So, um, what'cha looking for?"

The Doctor held up the pad for her to see. "Just a quick refresher to get my bearings. Ah, here we are. Just there," he pointed, "should be the Cedar Room. It's completely full of cedar chests and cedar closets and cedar everything. I love the smell of cedar. The other thing that room's got is ventilation shafts, and plenty of them. Y'see, I have the TARDIS waft that lovely aroma up to all the bedrooms! That's why they smell so marvelous. Anyway, it'll be an easy trick to tell the TARDIS to reroute one of those shafts directly to the control room, and voila! We can confront the unstoppable menace that's out to kill us all." He raised his eyebrows in delight and Amy smiled, clearly relieved that he had forgiven her, at least for the moment.

Rory, however, found himself compulsively rubbing his nose. In fact, he was quite allergic to the smell of cedar, and they'd had to block all the vents in their bedroom lest he break out in hives and fits of sneezing. He did not relish climbing through endless tubes filled with allergens, and he'd probably resemble a pink cactus by the time they reached their destination. Still, it couldn't be helped. Rory steeled himself for misery and came up behind the others just as the door irised open to reveal...

"No, no... this isn't right..." The Doctor backed away and the door closed again, but they'd all seen it. It was the dead control room. The one they'd just tried so hard to escape. In that brief moment, Rory could even make out the scorch marks on the walls and console. Then again, he thought something _was_ different, but what?

The Doctor hurried to the next door, and the next, but the rooms were all the same. Every door led to that same dead console, lit from above by blue spotlights and ringed by devastated finery. Finally, panting, the Doctor stopped and put his hands on his knees. Amy and Rory leaned against the wall. "They're all the same!" the Doctor gasped, "Every single one. That must have been at least thirty rooms, all the same! Why? The TARDIS knows better than that, she's not supposed to repeat..."

"Actually, that was only the fifteenth, I counted," Rory said, and immediately wished he'd kept his mouth shut.

Amy shot him a look. "Not helping. It...it couldn't be the Tree thing, could it? I mean, it couldn't have come this far in such a short amount of time. Could it?"

"No, no, the Tree couldn't have gotten past Level -100. In fact, it's probably all tangled up the in secondary logic circuits on Level -112." The Doctor walked slowly to the nearest door. It opened, and beyond lay yet another dead control room, identical to all the others. This time, he stood in the doorway, surveying it and thinking.

Rory took a close look as well, and then it hit him. "Doctor! There's something different about the rooms on this level. Different from the original, I mean, and I've just found it. Back down on Level -239, the tables in that room were all piled with loads of papers and books and things. Now look, the tables are bare, and some of the books are even gone from the bookshelves. Also, the boxes, the ones that the halves of the Tree came in, should be right there on the floor, but they're not. What happened to all of it?"

The Doctor, however, appeared to be ignoring him. "Of course! That's why the TARDIS is doing this. Right now, the Tree is mucking about in the secondary logic circuits 89 levels down. When I sent the telepathic message to my brilliant ship to move the lift earlier, I was concentrating on the dead control room as well. Now, normally she would ignore this, bright girl that she is, and focus on the message itself, but her logic centers are being consumed. In her addled state, she thought I wanted the room moved up here, over and over. Oh, you poor thing." He stroked the door frame sadly.

"Doctor, you're avoiding Rory's question," Amy said. The Doctor hung his head and rubbed his face with one hand. The other hand remained on the door frame. He suddenly reminded Rory of one of his medical school professors, far to old and tired to be teaching anymore, but still soldiering on simply because he didn't know how to do anything else. Finally, he spoke. "Amy, Rory, I know the TARDIS must seem like magic to you. It can translate almost anything, travel to any era, and mold itself to your every whim. However, I assure you that it is not magic, it's technology. And technology has its limits." He turned to face them, nine hundred years on his young face.

"I've picked up many things on my travels, people too, yes, but mostly things. I like to remember where I've been. The TARDIS very dutifully puts my souvenirs where I want them, or simply stores them in an N-space matrix until they are requested, which is basically like putting them in limbo. Think of a 'pattern buffer' from the transporters on Star Trek. If something isn't in the catalog of things I've collected, my dear ship can create some simple, generic things from scratch, such as hat stands and tables and butter knives. One thing it _cannot _do, however, is recreate a duplicate of a real object that has been destroyed."

"What? I'm sorry, I'm not getting it, Doctor," Rory admitted. A horrible realization crossed Amy's face, however, and she grabbed Rory's shoulder hard enough to hurt.

"Stay with me, Rory. Imagine if I took your left shoe, right now, and threw it down the lift shaft. Obviously you'd need a new one, and perhaps in my travels I've picked up a pair just like that, in which case the TARDIS would find it, rematerialize it, and presto! New shoe. However, if it couldn't find your shoe in the N-space matrix, it could make you a shoe, but it wouldn't be the same as the one you'd lost. That particular shoe is gone forever. Before I left Gallifrey for the last time, in those last days of the Time War when everything was was going to hell, I knew I wasn't coming back. Alive, anyway. I wanted to remember where I'd been, so I took a few things with me. Small things, just enough to remind me why I did what I did, and a few things to remind me what I was losing. The most depressing scrapbook in the world." He chuckled, but there was no mirth in it, and he wouldn't meet their eyes. "Once I'd...ended things, I found I wanted a fresh start. I was in my ninth incarnation by then, and my eighth incarnation's console room just didn't seem right anymore. It was damaged anyway, so I had the TARDIS make me a new one. I shut the old one down, and before I locked it I filled it with everything I'd taken from Gallifrey. Including both halves of the Tree. I wasn't paying enough attention. When the Tree got loose, it consumed everything in that room, and even the room itself. The TARDIS could recreate the room, because she created it in the first place, but everything else..." He made a fluttering motion with his fingers.

"All that's left of your race... Doctor, I'm s-" Amy moved to touch him, but the Doctor brushed her hand away. "No, you've said it before, no need to say it again." He sniffed and straightened his jacket. "Well now, there must be some way out of here. What say we go back to the lift and see if we can't shimmy up the shaft, eh?" They started slowly back to the lift, letting the door iris shut behind them. Rory hoped he never had to see that room again.

The lift was in sight. The doors were still open, and it looked as though there would be just enough room for them to climb on top of the car and find some way to make it to the control room. There was an ominous rumble from under the deckplates. The Doctor held up his hand and they stopped. There was silence, then another rumble. Rory tried to pinpoint the sound. A third rumble, this one louder yet. It was coming from the direction of the lift. "Something's coming up the shaft," the Doctor said. "The Tree is smart; it would have figured out by now that the quickest way up is a straight line..."

"What do we do?"

"Just...nobody move. We have no idea how it will react. It may pass us by." Suddenly the top of the jammed car visible through the open doors began to shake up and down, harder and harder. The noise was tremendous. There was one last screech of stressed metal, and the car disappeared entirely, dropping out of sight. A few seconds later, tiny silver fingers became visible on the inside of the shaft. They flowed and spread, finding the lip of the floor and pooling on the carpet. A small lake of silver began to form. The Doctor took a few steps closer, but scurried back quickly as the lake churned and frothed, extending a silver pseudopod into the air. This strange extension of the Tree hung motionless for a moment, before turning slowly back and forth, seeming to observe the three of them, despite having no obvious senses. Then, it focused quite clearly on Rory. It arched toward him, growing larger as more of itself flowed up the empty lift shaft to aid it. Rory backed away and the Doctor and Amy flattened themselves against the walls. "Rory," the Doctor said, "I don't know why, but the Tree is taking an interest in you."

"Yeah, think I can figure that out for myself, thanks!"

"Listen, Amy and I are going to find a way to stop it very shortly, but right now I need you to do something for me."

"What's that!"

"RUN!"

Next Time: Pursuit, Separation Anxiety, and a Very Convenient Grate


End file.
